IV is the cause for the DV
• A variable that interferes with the results
• Changes the IV
• The confounding v. affects the DV too so you don’t know what the cause of the DV is.
• Refers to many dozen of hundred ways that we are all different from one another.
• is done thru a survey.
Correlation method: • How variable are related to one another
• Measures the degree of relationships between two variables there is no attempt to manipulate
or control variables. Rather, naturally occurring variations on both variables are measured to
see if there are related.
• Correlations help us make predictions.
All group have to be similar in every way except the IV.
The alcohol example: 0oz | 2oz | 4oz
How do you make groups equivalent?
If you were to a out all the individuals for the 3 groups ^ that these groups would be equal to one
another, ways to make groups equal:
Using random assignment.
Its essential in survey research. The participants shouldn’t have a choice and there should be
placed all by chance.
By using random assignment you are assuming that individual difference variable are being evenly
distributed among groups making the groups equal.
One should have an equal number of gender varieties, age, and IQ level in each survey groups |all
depending on the type of the survey one does.
How do u know the random assignment is working?
We wont know.
Random selection vs. random assignment:
Ł Doing a study on child abuse and the child’s selfesteem.
create a scenario to see how the participants react emotionally.
you have to randomly assign three groups of children, abuse on group to the extreme, moderate
the other and leave the last group all alone. And do the survey at the end to see the result.
Correlation method: You have to question of groups of people in a survey to see how abused they have been as
children and further survey them in terms of the selfesteem level.
Every person will have two scores and from there you get to see the relationship between the
abused and their selfesteem.
But you can not infer a cause and relation affect.
Ł study of relation between fatigue/tiredness and test grades.
Have different groups of participants, have one groups get a normal and healthy # of sleep and the
other lesser and even close to nothing and have them all write a test to see the result.
Have everyone write a test and the further question them on the #of hours they have had. And from
there having both scores you can have a conclusion.
▯ ▯ the results being put on the graph should create a reasonable and understandable result that
would show the connection between variables.
Correlation coefficient (R):
• It’s a numerical value with an either + or – in front.
• Tells you the strength of the relationship, how strong are the variable are connected.
Impossible to get a correlation number over 1 ex. 1.02!!!
If u do get a 1.00, means that you have a perfect connection between the two variables, meaning
you have a perfect predictability.
If you get a zero, means that you have no correlation between the two variables
The closer to one, the correlation between variables are good and the closer to zero means no
[+]▯ the value of both variables change in the same direction.
As the fatigue increases to does the test marks or the opposite as the fatigue decrease
so does the test results.
 ▯ the value of both variables change in the oppos